New options framework for the ports
for maintainers:
it introduces 3 different types of options: simple, multi and single:
- simple options are the same as the current options (i.e. on or off.)
- multi options are options where at least one must be set (1-N).
- single options are options where one and only one must be set (exclusive
options).
for users:
- OPTIONS_SET: globally enable some options
- OPTIONS_UNSET: globally disable some options
- ${UNIQUENAME}_SET: enable per-port choice of options
- ${UNIQUENAME}_UNSET: disable per-port choice of options
For compatibility the old OPTIONS framework is now working on top of the new one
The options previously set with old OPTIONS are imported and converted
transparently.
A new knob NO_DIALOG if defined in the the config-conditional target is ignored
(prevent the dialog(1) ui to show up.
Thanks to all people involved:
beat@, crees@, Bryan Drewery, linimon@, novel@ and others, for testing,
comments, patches

* Update to 8.71.[1] Changes include:
- Support for tiff file output is now provided using the libtiff
implementation rather than our more limited native code as in
previous releases. There is also a new 'tiffsep1' output
device which produces halftoned separations at 1
bit-per-pixel, in contrast to the 'tiffsep' device which
produces 8 bit-per-pixel plates.
- The graphics library has been updated to provide more accurate
scan conversion of vector art including fixes to dash
behavior, transparent stroked paths, thick stroked paths,
radial shadings, xps cap handling, "pie" joins, degenerate
beziers, improved handling of dropouts in thin strokes and
better thin axis-aligned strokes.
* Fix cairo support. GS_cairo is added to the drivers list (this
is disabled by default). When WITH_CAIRO is defined, GS_cairo
will be set by default.[2]
PR: ports/144111[1]
PR: ports/137634[2]
PR: ports/145248[2]

Update to 8.70. Changes include:
- This release fixes a large number of issues with transparency,
especially as it interacts with color space conversion, mask
contexts and patterns. There have also been a number of
significant fixes to font handling, especially when generating
PDF. And there are numerous robustness, correctness and
performance improvements.
- New generic Esc/Page devices, eplmono and eplcolor were added
to the contrib directory. A new cdnj500 device was added to
support the HP DesignJet 500.
- The licensing of the Free version of the core Ghostscript code
has been changed to GPLv3 or later. Previously, the core code